<output>@(result is null ? "Loading" : result.ToString())</output>

@code
{
  int? result = 0;

  public async Task Calculate(int x, int y)
  {
      result = null;
      StateHasChanged();
      // Simulate an asynchronous operation, like fetching data.
      await Task.Delay(500);
      result = x + y;
      StateHasChanged();
  }
}